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<div class="titlepage"><div><div><h4 class="title">
<a name="boost_asio.reference.io_context.run"></a><a class="link" href="run.html" title="io_context::run">io_context::run</a>
</h4></div></div></div>
<p>
          <a class="indexterm" name="boost_asio.indexterm.io_context.run"></a> 
Run the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput"><span class="identifier">io_context</span></code></a> object's event processing
          loop.
        </p>
<pre class="programlisting"><span class="identifier">count_type</span> <span class="identifier">run</span><span class="special">();</span>
</pre>
<p>
          The <code class="computeroutput"><span class="identifier">run</span><span class="special">()</span></code>
          function blocks until all work has finished and there are no more handlers
          to be dispatched, or until the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput"><span class="identifier">io_context</span></code></a> has been stopped.
        </p>
<p>
          Multiple threads may call the <code class="computeroutput"><span class="identifier">run</span><span class="special">()</span></code> function to set up a pool of threads
          from which the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput"><span class="identifier">io_context</span></code></a> may execute handlers.
          All threads that are waiting in the pool are equivalent and the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput"><span class="identifier">io_context</span></code></a> may choose any one
          of them to invoke a handler.
        </p>
<p>
          A normal exit from the <code class="computeroutput"><span class="identifier">run</span><span class="special">()</span></code> function implies that the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput"><span class="identifier">io_context</span></code></a> object is stopped (the
          <code class="computeroutput"><span class="identifier">stopped</span><span class="special">()</span></code>
          function returns <code class="computeroutput"><span class="keyword">true</span></code>). Subsequent
          calls to <code class="computeroutput"><span class="identifier">run</span><span class="special">()</span></code>,
          <code class="computeroutput"><span class="identifier">run_one</span><span class="special">()</span></code>,
          <code class="computeroutput"><span class="identifier">poll</span><span class="special">()</span></code>
          or <code class="computeroutput"><span class="identifier">poll_one</span><span class="special">()</span></code>
          will return immediately unless there is a prior call to <code class="computeroutput"><span class="identifier">restart</span><span class="special">()</span></code>.
        </p>
<h6>
<a name="boost_asio.reference.io_context.run.h0"></a>
          <span class="phrase"><a name="boost_asio.reference.io_context.run.return_value"></a></span><a class="link" href="run.html#boost_asio.reference.io_context.run.return_value">Return
          Value</a>
        </h6>
<p>
          The number of handlers that were executed.
        </p>
<h6>
<a name="boost_asio.reference.io_context.run.h1"></a>
          <span class="phrase"><a name="boost_asio.reference.io_context.run.remarks"></a></span><a class="link" href="run.html#boost_asio.reference.io_context.run.remarks">Remarks</a>
        </h6>
<p>
          Calling the <code class="computeroutput"><span class="identifier">run</span><span class="special">()</span></code>
          function from a thread that is currently calling one of <code class="computeroutput"><span class="identifier">run</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">run_one</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">run_for</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">run_until</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">poll</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">poll_one</span><span class="special">()</span></code> on the same <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput"><span class="identifier">io_context</span></code></a> object may introduce
          the potential for deadlock. It is the caller's responsibility to avoid
          this.
        </p>
<p>
          The <code class="computeroutput"><span class="identifier">poll</span><span class="special">()</span></code>
          function may also be used to dispatch ready handlers, but without blocking.
        </p>
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<div class="copyright-footer">Copyright © 2003-2025 Christopher M.
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        Distributed under the Boost Software License, Version 1.0. (See accompanying
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